A magnetic part including a coil and a magnetic core where the coil is disposed, such as a reactor or a motor, is used in various fields. For example, Patent Literature 1 discloses a reactor used as a circuit component of a converter mounted on a vehicle such as a hybrid vehicle. Further, Patent Literature 1 discloses, as a material structuring a magnetic core included in the reactor, a composite material made up of a magnetic substance powder such as a pure iron powder, and a resin (a binder resin) including the powder. The composite material can be manufactured by packing a mixture obtained by mixing a raw-material magnetic substance powder and an uncured liquid resin in a mold assembly of a desired shape or the like, and then curing the resin.